First, looks like you are new to the forum, welcome.
In addition to looking into what JW Firebird suggested (he is super knowledgeable), you might want to isolate the problems a bit more. You may have more than one problem.
I would do a scan and see what the service engine soon light was indicating. That may give another avenue to troubleshoot.
Keep us in the loop on how you you are doing with this. There are some knowledgeable people here on the Jimmy/Blazer/Bravada.